Slip form curb and gutter machine

ABSTRACT

Self-propelled curb and gutter forming machine mounted on continuous traction tread devices. A curb mold form is suspended from the main frame of the machine and extends between the continuous traction tread devices. The main frame of the machine is suspended from the tread devices on three jacks, two of which are provided on one side of the machine and control the grade and a third of which is provided on the opposite side of the machine and controls the slope of the main frame and curb mold form. The curb mold form is vertically pivoted at its front end to a drawbar at the front of the main frame and is suspended from the main frame at its rear end to move laterally about the axis of the vertical pivot. The continuous traction tread devices are driven by independent hydraulic motors, controlled by a variable flow divider valve either manually operated or automatically operated under the control of a sensor biased into engagement with a line extending along the side of the roadway. The three jacks are in the form of self-locking screw jacks driven by individual hydraulic motors. The two jacks on one side of the machine conform the machine to the grade of the roadway and are controlled by grade sensors. The hydraulic jack on the opposite side of the machine conforms the machine to the slope of the roadway and is controlled by a pendulum control.

[451 ,Ian. 1%, I972 SL111? IFIBEIM C'UEIILI AND G'UTTIEEI MAQIIHNIE [72]Inventors: Richard I). Larsen, Denver, Iowa; Harold E. Miller,Milwaukee, Wis.

Qurbrnaster of America, Inc, Cedar Falls, Iowa [22] Filed: Feb. 2, 19711[21] Appl. No.: 7,709

[73] Assignee:

[52] US. Cl [5 1 Int. Cl. [5 8 ll ield of Search ....94/4l6, 180/648..E1lc 119/30 ..94/46; ISO/6.48

Primary ExaminerJacob L. Nackenoff Attorney-Hill, Sherman, Meroni, Gross& Simpson [5 7] ABSTRACT Self-propelled curb and gutter forming machinemounted on continuous traction tread devices. A curb mold form issuspended from the main frame of the machine and extends between thecontinuous traction tread devices. The main frame of the machine issuspended from the tread devices on three jacks, two of which areprovided on one side of the machine and control the grade and] a thirdof which is provided on the opposite side of the machine and controlsthe slope of the main frame and curb mold form. The curb mold form isvertically pivoted at its front end to a drawbar at the front of themain frame and is suspended from the main frame at its rear end to movelaterally about the axis of the vertical pivot. The continuous tractiontread devices are driven by independent hydraulic motors, controlled bya variable flow divider valve either manually operated or automaticallyoperated under the control of a sensor biased into engagement with aline extending along the side of the roadway. The three jacks are in theform of self-locking screw jacks driven by individual hydraulic motors.The two jacks on one side of the machine conform the machine to thegrade of the roadway and are controlled by grade sensors. The hydraulicjack on the opposite side of the machine conforms the machine to theslope of the roadway and is controlled by a pendulum control.

22 Claims, 9 Drawing Figures PATENTEB JAN 1 8 i972 SHEET M BF 7 INVIZN'I'ORS PATENTED .ms 1 8 m2 SHEET 5 0F 7 SILIIF l 'Oiilth/i Glllllfrl AND MACHINE SUMMARY AND OBJECTS OF THE INVENTION Endless tractionmounted curb and gutter forming apparatus drawing a curb mold form alonga roadway and accommodating limited lateral movement of the mold formabout its front end, to conform to the line of the roadway, in whichendless traction devices suspend the main frame of the apparatusincluding the mold form by a three-point selflocking suspension,conforming the apparatus to the grade and slope of the roadway under theautomatic control of a line extending along the roadway, and in whichsteering of the apparatus may be manual or automatic under the controlof the same line. Y

A principal object of the present invention is to provide an improvedform of self-propelled curb and gutter forming apparatus arranged with aview toward minimum manual control of the apparatus.

Another object of the invention is to provide a novel and improved formof unitary self-propelled curb and gutter forming apparatus capable offorming a concrete curb and gutter while travelling along the edge of aroadway, without the necessity of providing the usual rails along whichthe apparatus has formerly traveled.

Another object of the invention is to improve upon the curb and guttermolding apparatus heretofore in use, by suspending the main frame of theapparatus from laterally spaced continuous traction tread devices, andsuspending the mold form from the front of the main frame to extendbetween the continuous traction devices and move laterally relativethereto to readily conform to the line of the roadway.

Another object of the invention is to provide an improved curb andgutter forming machine having a simplified and improved form ofsuspension for the main frame of the machine from the continuoustraction tread devices supporting and propelling the machine,accommodating the machine to conform to variations in the grade andslope of the roadway and holding the frame in its various selectedpositions, determined by the slope and grade of the roadway, with noattention from the operator of the machine.

A still further object of the invention is to provide an improved formof support and propelling arrangement for a curb and gutter formingmachine, all under the control of a line extending along the edge of theroadway, in which manual control and operation of the apparatusindependently of the line may readily be selected.

A still further object of the invention is to provide a simplified andimproved self-contained self-propelled machine for forming curbs andgutters in which continuous traction tread devices riding on thesubgrade take the place of the usual support rails for the apparatus.

A still further object of the invention is to provide an apparatus forforming concrete curbs and gutters in a continuous operation, arrangedwith a view toward utmost simplicity in construction and efficiency inoperation.

Other objects, features and advantages of the invention will be readilyapparent from the following description of a preferred embodimentthereof, taken in conjunction with the accompanying drawings, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a curb andgutter forming apparatus constructed in accordance with the principlesof the present invention, looking at the apparatus towards the front andone side thereof.

FIG. 2 is a view in side elevation of the apparatus shown in FIG. ll,looking at the opposite side of the apparatus from that shown in FIG. Iwith certain parts broken away and certain other parts removed.

FIG. 3 is a front end view of the apparatus with certain parts removed.

FIG. 4 is a general diagrammatic view in side elevation of the apparatuslooking at the opposite side of the apparatus from FIG. 3, with certainparts removed in order to more clearly show the sensor arrangement forsteering and conforming the apparatus to the grade of the roadway.

FIG. 5 is an exploded view showing; the main frame of the apparatus andcertain suspension and control parts therefor.

FIG. 6 is a partial fragmentary exploded view, with parts broken awayand certain other parts shown in section, in order to illustrate thestructure of the jacks suspending the main frame from the continuoustraction tread devices.

FIG. 7 is a generally perspective exploded view of the mold form andhopper with certain parts broken away and certain other parts shown insection.

FIG. d is a fluid pressure diagram illustrating the piping connectionsto the grade and slope conforming jacks, suspending the main frame fromthe continuous traction tread devices; and

FIG. 9 is a fluid diagram illustrating the piping connections andcontrols for operating the fluid pressure operated motors for drivingthe continuous traction tread devices.

DESCRIPTION OF PREFERRED EMBODIMENT OF INVENTION In FIG. I of thedrawings, we have shown a generally diagrammatic perspective view of acurb and gutter forming machine III, for laying a curb and gutter alongthe side of a roadway and including a main frame llll suspended fromlaterally spaced continuous traction tread devices 112 on jacks A and Bat one side of the machine and a jack C at the op posite side of themachine. Said jacks conform said main frame and a mold form 13 carriedby said main frame, between said laterally spaced continuous tractiontread devices, to the slope and grade of the roadway, in a manner whichwill hereinafter more clearly appear as this specification proceeds.

The continuous traction tread devices 112 may be of a conventional form,and are each driven from an individual fluid pressure operated motor 15having driving connection with the associated tread devices at the frontend thereof through a conventional sprocket (not shown) meshing with thetread of the tread devices in a well-known manner. The continuoustraction tread devices I2 are trained about tread frames 16 formingmounting means for the motors I5 and having a series of rollers 17spaced along the lower end portions of said tread frames and engagingthe lower runs of the tread devices.

The jacks A, B and C are each of a similar construction and are shown inFIG. 6 as being screwjacks. Each jack is in the form of a verticallyextending tube shown as being a hollow vertically extending rectangularpost Id telescopic within a rectangular tube or post I9 extendingupwardly therefrom and forming a suspension means for the main frame ll.As shown in FIGS. 1 and 5, the post I9 of the jack A is partiallyrecessed in a side frame member 20 of the main frame II, and may bewelded or otherwise secured thereto. The post I9 of the jack A extendsalong the corner of a side frame member 21 spaced outwardly of the sideframe member 20 and a cross frame member 22 and may be welded orotherwise secured thereto. The post 19 of the jack C is shown in FIG. 5as partially recessed within a side frame member 23, complementary tothe side frame member 20 and may be welded or otherwise secured thereto.

The jacks A, B and C are hydraulic jacks and are shown in FIG. 6 asbeing self-locking screw jacks, and are particularly advantageous in useas suspending the main frame ill from the continuous traction treaddevices 112 and conforming the main frame to various slopes and gradesof the roadway, due to the self-locking features of the jacks which makeit unnecessary to provide a means for holding the jacks in means toaccommodate for leakage in the fluid pressure system. Each jackgenerally includes the hydraulic motor 25 mounted on a plate 26 disposedadjacent the top of the post 19 and suitably secured thereto. Thehydraulic motor 25 is a reversible motor having a drive shaft 27 coupledwith a lead screw 29 through a coupler 30. The lead screw 29 extendsdownwardly through the plate 26 along a support tube 31 dependingtherefrom, and forming a support for a thrust bearing 32 forming athrust bearing for the lower end of the coupler 30. A second thrustbearing 33 is carried in the sleeve 3i in a suitable manner and forms athrust bearing for the upper end portion of the coupler 30, andcooperates with the thrust bearing 32 to retain the lead screw 29 fromvertical movement relative to the post 19. The lower end portion of thelead screw 29 is threaded within a thrust nut 35 secured to a mountingplate 36 suitably mounted in the tube 18, adjacent the upper endthereof. The thrust nut is secured to the mounting plate as by a seriesof bolts 37, or other securing means. A spring 39 encircles each bolt 37and is interposed between the underside of the thrust nut and the top ofthe mounting plate 36 to cushion the thrust nut 35. The threads of thelead screw 29 and thrust nut 35 may be acme self-locking threads, tolock the jack in position when the motor 25 is not in operation. Othertypes of screws, such as ball types of nuts and screws may also be used.A cap 40 is provided for each post 19 and forms a protective closure forthe motor 25.

Each post 18 is mounted on and extends upwardly of a yoke 41 having legs42 extending downwardly along opposite sides of the continuous tractiontread devices 12 and secured to the associated tread frame 16 as bytransverse pivot members 43.

A stabilizer 44 is provided on the side of the machine containing thehydraulic jack C, to stabilize this side of the machine. The stabilizer44 includes a rectangular hollow post 45 secured to the main frame 11.at the corner of a hollow cross frame member 46 and a side frame member47, spaced outwardly of the side frame member 23, and welded orotherwise secured thereto. The cross frame member 46 is shown as beinghollow and as having a hollow bar 48 mounted therein and extendinginwardly therefrom within a hollow interior portion of the crossbar 22.The connection between the bar 48 and crossbar 22 accommodates wideningof the frame for various widths of gutters or paving on principlessimilar to those shown and described in the Larsen et al. US. Pat. No.3,202,068, dated Aug. 24, 1965 assigned to the assignee of the presentinvention, and no part of the present invention so not herein shown ordescribed further.

The hollow rectangular post 45, as shown in FIG. 2 has a rectangulartube 49 telescopically mounted therein and extending upwardly therealongfrom a yoke 50 extending along opposite sides of an associatedcontinuous traction tread device 12 and tread frame 16, and transverselypivoted to said tread frame, as by a pivot member 51.

The crossbar 22 of the main frame 11 has a platform 53 suitably hungthereon and secured thereto and forming a support for an internalcombustion engine (not shown), a pump 56 driven from said engine, and anauxiliary generator 57, supplying the power to operate vibrators 59 in ahopper 60, for the concrete, and set into operation upon the pouring ofconcrete in said hopper to maintain a uniform flow of concrete from thehopper 60 into the mold 13. The engine may be a conventional form ofinternal combustion engine and may also drive an alternator (not shown)for maintaining the batteries of the machine charged The mounting forthe platform 53 on the crossbeam 22 also forms a mounting for adownwardly facing generally U-shaped bracket 61 (FIG. 3) forming amounting for a control box 63 extending rearwardly of said bracketmember and for a pendulum control box 64 having a pendulum 65 thereincontrolling the supply of fluid to the slope control jack C to tilt themain frame 11 and mold T3 to conform to the slope of the pavement. Thependulum control 65 is only diagrammatically shown herein, and may be ofany conventional form. Said pendulum control in structure is no part ofthe present invention except insofar as it forms a control for thesupply of fluid under pressure to the jack C, so need not herein beshown or described in detail.

Referring now in particular to FIGS 2, 3, 5 and 7 and the suspension ofthe mold form or mule 13 from the main frame ll, as well as theconstruction of said mold form, the mold form 113 is in the general formof an inverted pan generally conforming to the shape of the curb andgutter to be paved. Said mold form extends between the continuoustraction tread devices 12 and has the hopper 60 mounted in a bottomopening hopper receptacle 66 at the forward end of said mold form, andopening to the interior of said mold form.

The mold form 13 may be of various forms depending upon the requiredcurb and gutter to be molded, as for example, the form may be so formedas to form the curb only, or to form the curb and gutter or to form thegutter only or to mold traffic medians or to widen the pavement. Asshown in FIGS. 3 and 7, the mold form 13 has a vertical front wall 67,having a bottom opening recess 69 therein forming a relief recess,accommodating the concrete to flow therethrough when an excess ofconcrete may be poured into the mold form. Said recess 69 has retainerplows 70 extending forwardly of opposite sides thereof generallytriangular in plan and converging toward apices at their forward ends,to retain excess concrete to the mold form, as the machine advancesalong the pavement.

The front wall 67 has a cutoff plate 71 pivoted to the inside thereof,beneath the discharge end of the hopper 60, for movement about an axisextending transversely of the machine. The cutoff plate 71 is adjustablymoved by an adjustment tube 72 and lead screw 73 to restrict thedischarge area of the hopper 60 where required. The lead screw 73 isthreaded in a nut 74, at the outer end of the adjustment tube 72 and isalso threaded in an acme nut 75 carried in a bracket 76 and forming ahanger for said lead screw. Said lead screw extends through the bracket76 and has a hand wheel 77 secured to its outer end, for turning saidlead screw and effecting adjustment of the cutoff plate or valve 71. Thehanger 76 is carried between bracket members 79 extending forwardly ofthe front wall 67, on a nut and bolt 80 forming a pivotal mounting forsaid hanger between said bracket members, as shown in the exploded viewof FIG. 7.

The hopper 60 has converging end walls 81, 81 and sidewalls 82, 82converging towards their lower ends to a rectangular discharge endportion fitting within the receptacle 66, and suitably secured to saidreceptacle. Said hopper may be removed for cleaning or changing the formand size of the hopper, where required.

The suspension means for the curb mold form 13 from the main frame 11comprises a drawbar 83, shown in FIG. 7 as being a hollow rectangularsection and suspended from the main frame 11 on threaded rods or bolts85, extending through opposite ends of said draw bar and retainedthereto as by lock nuts 86 threaded on said bolts and tightened intoengagement with the top and bottom sides of said draw bar. The bolts 85,as shown in FIG. 5 depend from generally T-shaped mounting members 87mounted on bars 88 extending inwardly of the side frame members 20 and23 of the main frame 11 and just rearwardly of a front crossbar 89 ofsaid main frame. The bars 88 are shown as being hollow tubular bars,having cylindrical outer peripheries forming pivotal mountings for themounting brackets or hangers 87. The mounting bolts extend within thedepending stems of the mounting brackets and are secured thereto by pinsor screws 90, (FIG. 5). Collars 91 limit lateral movement of the T-shaped mounting brackets along the bars 88.

The drawbar 83 has a threaded rod 93 depending from the center thereof,(FIG. 7) in substantial alignment with the longitudinal center of themachine and having a collar 94 secured to its upper end, abutting thetop surface of the drawbar 83. A nut and bolt 95 extends through thecollar 94 and threaded rod 93 to suspend the threaded rod 93 from thedrawbar 83. The threaded rod 93 may be of a relatively large diameterand forms a pivotal suspension mounting for the forward end portion ofthe mold form 13, accommodating pivotal movement of said mold formbetween the continuous traction tread devices l2, 12, to enable the moldform to conform to the line of the roadway.

As shown in ZFTGS. 2 and 7, the threaded rod 93 extends H i may bewelded or otherwise secured to the front wall d7. Gusset plates Millserve to reinforce the vertical and horizontal legs of said anglebracket on opposite sides of the apertured portion 96 thereof. Thethreaded rod 93 is retained to the leg 9'7 of the angle bracket 9'9, asby nuts ti lil. 'l') threaded on said rod and abutting the top andbottom surfaces of the horizontal leg 97. Any suitable locking means maybe provided to lock the nuts llll ll in place.

The rear end portion of the mold form l3 has a hanger wi l extendingupwardly of opposite sides thereof including a crossbar lltM- extendingacross the mold form and suitably gusseted to said hanger. The crossbarhas collars lltl fi suitably mounted thereon and extending upwardlytherefrom, adjacent opposite ends thereof, and forming mountings forthreaded suspension rods lilo, extending within and secured to saidcollars as by nuts and bolts illl'l'. The suspension rods lltlti extendthrough the bases of upwardly facing U'shaped yolces li -W and aresuitably secured to said yokes as by nuts lltl threaded on saidsuspension rods and locked thereto in a suitable manner.

Each yolre 1W9 extends along opposite sides of a shaft llllll (HO. 5)and is suspended from said shaft as by a flanged spool or roller M2,running along and supporting the yoke and curb form on the associatedshaft ill for a limited lateral movement therealong. A second spool orroller llfil is mounted between the legs of the yoke Th9 to engage theunderside of the associated shaft ill. and limit upward movement of themold form relative to the main frame As shown in FlG. 5, one shaft Jillis mounted on and extends inwardly or" a side frame member l? rearwardlyof the stabilizer Aid. A coaxial shaft llll extends inwardly of sideframe member 27: rearwardly of the suspension jack 8. Each shaft tillhas spaced collars 11115 mounted thereon limiting lateral movement ofthe rollers M2 along said shafts and thus limiting lateral movement ofthe mold form about the axis of the front threaded shaft 93 dependingfrom the drawbar b3.

As is customary with mold forms, the bulk of the mold form is made fromsheet steel metal while a rear finishing extension llllb of the moldform is provided extending rearwardly of the hanger 1103 and conformingto the form of the mold form. The finishing section llllb of the moldform may be made from stainless steel and serves to impart a smoothfinish to the curb and gutter as the mold form is drawn therealong. Thesection lib may be detachably secured to form a rear continuation of themold form, as by turnbuckles 11117, and connector links lllld, in anysuitable manner. if desired, drag rails (not shown) may extendrearwardly of the mold and form continuations of opposite sides thereofand the finishing extension may be either in advance or rearwardly ofsaid drag rails, depending upon the particular surface poured.

in H6. '7 one vibrator 59 is shown as extending into the hopper an tovibrate the concrete as poured into said hopper. Said vibrator orvibrators assures a uniform flow of concrete from said hopper to theadvance end of the mold form l3 and takes the place of the angersheretofore used for this purpose. in many cases more than one vibratoris provided, particularly where the hopper is relatively wide. in suchcases one vibrator may be positioned adjacent one end of the hopper,while the other vibrator may be positioned adjacent the opposite end ofthe hopper. The vibrator 59 may be of a conventional form, having avibrating head in the hopper 6d, vibratorily driven by a vibrator motorllZll through a flexible shaft (not shown) contained within a casing1232. The vibrator motor is energized by the auxiliary generator 57,driven from the internal combustion engine 55. Since the vibrator isconven tional and is no part of the present invention, a detaileddescription thereof is not necessary for a clear understanding of thepresent invention.

Referring now to the control for the grade control jacks A and B and theslope control jack C, as shown in lFlG. 4, grade control sensors R23 andfor the respective jacks A and B are mounted at the front and rear ofthe machine along the outer side thereof relatively to the subgrade orroadway, to effect operation of said jacks and conform the machineto thegrade of the roadway. The slope control pendulum 65 is mounted above andin advance of the control box or console as, containing the controls forcontrolling the several operations of the machine, and disposed inadvance of an operators platform lid.

The grade control sensors 1123 and H24 engage under a grade line H27strung along the subgrade of the pavement, along which the tractiontread devices travel, and disposed above said subgrade. The sensor i123includes a control housing i229 mounted on the lower end of a jack T30and raised or lowered by said jaclr to set a sensor member ll3l toengage under the line M7. The sensor member ll3ll is mounted on the endof an arm T32 pivoted to the housing 129 on a pivot pin T33. Acounterweight extends from the pivot pin 133 in an opposite directionfrom the arm H32, and serves to bias the sensor member llll intoengagement under the grade line 127. The housing 129 may contain thecontrols controlling energization of the valves for supplying llluidpressure to and releasing fluid pressure from the jack A. The controlsmay include a conventional potentiometer (not shown) transmittingsignals to an electrical control circuit (not shown) and at a zeroposition when the sensor is at a zero position and the jack A hasmaintained the machine in alignment with the grade line, and moving toone side or the other of zero, to supply fluid under pressure to thejack A, to elevate or lower the main frame relative to its supportingcontinuous tread device. The potentiometer and electric controls may beof several conventional forms and form no part ofthe present invention,so need not herein be shown or described further.

The housing T29 is mounted on the lower end of the jack TM. The jackllZlll may be a self-locking type of screw jack, raising and loweringthe housing T29 and sensor member 131, upon turning movement of a handwheel 137.

As diagrammatically shown in FM]. 4, the screwjack 130 is mounted on abracket member i139 adjustably movable along a horizontal support armMb. The bracket member T39 may be adjustably moved along the arm Mill inaccordance with the position of the grade line 127 relative to themachine, and held in position as by a thumb screw Mil or any othersuitable securing means. The arm Mill in turn is mounted on the upperend of a shaft M2 mounted on a bracket member M3. The bracket member M3is suitably secured to the outer face of the post l9, and extendsoutwardly therefrom. A thumb screw lid-4i or other securing means isprovided to hold the shaft 142 in a selected position, determined by theposition of the grade line i237 relative to the side of the vehicle.

The sensor 112d controlling the supply of fluid under pressure to thehydraulic jack B is like the sensor 123 and includes a sensor member M5pivoted to a control housing M6 and biased into engagement with a gradeline R27 by a counterweight Md. The control housing M6 is carried on thelower end ofa screwjack M9 like the jaclr 13b and is operated by a handwheel lfit) at the upper end of said jack. THc sensor 124 is positionedclosely adjacent the curb mold form 13 at the rear end portion of thesmoothing trough or finishing section lid of said mold form. The twosensors H23 and T24 are thus positioned beyond the forward and rear endsof the continuous traction tread devices T2 to more readily anticipatevariations in the grade and tendencies of the machine to diverge fromthe grade line.

The screw jack B49 is mounted on a bracket member llSll adjustablymovable along a bracket ann T53 extending from a depending verticalshaft portion 155. The vertical shaft portion T55 of the bracket arm T53is mounted in a support tube llfid, extending upwardly of the forwardend portion of the platform Mb. The arm T53 may be adiustably movedabout the axis of the shaft and held in position as by a thumb screw15%, while the jack M9 may be adjustably moved about its axis and heldin a selected position by a thumb screw T59 threaded in the bracketmember H511.

The grade and slope control hydraulic circuit has parts common to thehydraulic steering circuit and includes a tank 160 containing ahydraulic fluid, such as oil, commonly used in fluid control systems andhaving fluid connection with the intake of the pump 56 for supplyingfluid thereto. The outlet of said pump has connection witha flow controlvalve 161, through a fluid pressure line 162.

The flow control valve 161 may be of a conventional form and includes astart and stop lever 163 operable to block the flow of fluid to thesystem and a relief valve 165 returning fluid to tank when the lever 163is in a stop position. The flow control valve also includes a knob 166varying the flow of fluid through the valve to a pressure line 167,supplying fluid under pressure to valve blocks 170, 171 and 172 mountedon a base plate 168.

The flow control valve also includes a knob 169 operating a valve member(not shown) of said flow control valve, which controls the quantity offluid supplied to the hydraulic motors 15, to vary the traveling speedof the machine. The flow control valve 161 including the valve partsthereof operated by the knobs 166 and 169 may be of any conventionalform and are no part of the present invention so need not herein beshown or described further.

The three valve blocks 170, 171 and 172 have solenoid operated valves(not shown) therein controlling the supply of fluid under pressure tothe jacks A, B and C, in accordance with the positions of the respectivegrade sensors 123 and 124. A steering control valve block 173 is mountedon the base plate 168, beneath the valves 170, 171 and 172.

The control console contains electric circuitry means for energizingsolenoids 176 and 177 of the valve in the valve block 170, 178 and 179for the valve in the valve block 171 and 180 and 181 for the valve inthe valve block 172, energized by signals from the sensors 123 and 124.The solenoids 170 to 181 inclusive may also be energized manually by theselective operation of a series of switches 183 and 184 on the topsurface of the control console 63. A third switch 185 is provided inalignment with the switches 183 and 184 on the top of the console and iseffective to connect the electric circuitry within the control consolefor manual operation by operation of the switches 183 and 184 or forautomatic operation by operation of the sensors 123 and 124.

In alignment with the switches 185, 183 and 184 is a fourth switch 186operable when the switch 185 is in the manual position to energize thesolenoids 180 and 181 and control the supply of fluid under pressure tothe third jack C, to manually control the slope of the machine. Theelectric circuitry within the control console may be of any conventionalform and is no part of the present invention so need not herein be shownor described further.

The control console also has a series of switches 187, 188 and 189thereon spaced beneath the switches 185 and 186 inclusive, to effect themanual control of the traction motors 15, 15. The switch 188 may set thesystem for manual or automatic control of the continuous traction treaddevices 12, 12. The switch 187 to the left of the switch 188 mayenergize solenoids 190, provided to operate the valve in the valve block173, to supply fluid under pressure to a pressure line 193 connectedwith a variable flow divider valve 212, supplying fluid under pressureto said valve to effect driving of the motors 15, 15 in a direction tomove the machine forwardly or to move the valve in the valve block 173to effect reverse travel of the motors 15 and continuous traction treaddevices driven thereby, as will hereinafter more clearly appear as thisspecification proceeds.

It should be understood that the switches 183, and 186 are not manuallyoperated unless the switch 185 is in a manual position, and that theswitches 188 and 189 are not manually operated unless the switch 187 isin a manual position. The console also has a meter 197 thereon having adial 199 indicating the direction of travel of the vehicle. That is,when the dial is in a zero straight-ahead position the vehicle istraveling in a straight line. When the dial is to the right of zero thevehicle will be traveling toward the right and when to the left the ofzero will be traveling toward the left. The usual ammeter is alsoprovided on the console, to the right of the switches 187, 188 and 189.

The slope control pendulum 65 in the control housing or console 63 isprovided to control operation of the fluid pressure operated jack Cthrough the valve in the valve block 172 under the control of solenoids180 and 181. The pendulum and controls in the housing may be of anywell-known'commercial construction commonly used on paver finishers andgraders, and are effective when the control knob 185 is in an automaticposition to energize either solenoid 180 or 181 to supply fluid underpressure through a pressure line 201 or 202 to rotate the fluid pressureoperated motor driving the lead screw 29 of the jack C in one directionor another dependent upon the lateral slope of the roadway, to maintainthe paving machine in conformance with said lateral slope. The valveblock has a return fluid connection 203 leading therefrom havingconnection with a return line 204 returning fluid back to tank 160. Thevalve blocks 171 and 172 may have similar return lines connected withthe return line 204.

When the switch 185 is in a manual position, the solenoids or 181 may beselectively energized by turning movement of the switch 186 in onedirection or another to tilt the machine to conform to the slope of theroadway.

When the sensors 123 and 124 have been adjusted to come under and engagethe sensor line 127, assuming the line 127 conforms to the grade of theroadway, the switch may be turned to its automatic position. If the mainframe 11 and mold form 13 starts to move off grade the sensor 123 maythen generate signals to effect energization of the solenoids 176 or 177to operate the valve in the valve block 171 to supply fluid underpressure through the pressure line 205 or 206 to operate the jack motor25 to elevate or lower the front jack A. The sensor 124 may alsogenerate signals to energize either of the solenoids 178 or 179 to movethe valve in the valve block 171 to supply fluid under pressure to themotor 25 for the rear jack B through pressure lines 207 or 208, tooperate said motor to raise or lower the jack in accordance withrequirements to conform the main frame and mold form to the grade. Thetwo jacks A and B may be independently or simultaneously operated, inaccordance with the requirements necessary to maintain the main frame 11and mold form 13 on grade.

Referring now to the steering circuit under the control of the switches187, 188 and 189 on the top face of the control console, the steeringcircuit, as has been evident from the foregoing description of the gradeand slope control circuit is under the control of the knob 169adjustable to control the volume of fluid supplied to the valve block173 through a pressure line 209 leading from flow control valve 161. Thepres sure line 209 has a variable relief valve 210 connected therein torelive pressure upon closing of the valve in the valve block 173 or whenthe motors 15 may stall. The valve block 173 is connected to tank 160through the return line 204 previously mentioned. A pressure line 211leads from the valve block 173 to supply fluid under pressure to thevariable flow divider valve 212. The variable flow divider valve 212 hasfluid pressure connection with the two motors 15, 15 through a pressureline 213 connected with the left-hand motor and a pressure line 215connected with the right-hand motor. The flow divider valve 212 dividesthe volume of oil supplied by the pressure line 211 to the pressurelines 213 and 215 and supplies equal amounts of fluid to each pressureline to effect rotation of the two motors 15, 15 at the same rates ofspeed for straight ahead travel of the machine. The flow divider valve212 is varied to vary the flow fluid to one motor or the other inaccordance with the direction it is desired the machine deviate fromstraight line travel by operation of a motor 216 energized to vary theposition of the variable flow divider valve 212 upon the receiving of asignal from a sensor 217 engaging the line 127 on the inside thereof.The motor 216 has suitable reduction gearing contained within itshousing and has driving connection with the variable flow divider 212 tovary the division of fluid delivered by said valve, as by a timer beltdrive 218.

wa t The sensor 217 includes a sensor member 219 pivotally mounted inthe housing 221), which may house a potentiometer or other device tosend a signal to the motor 216 to effect steering of the machine in therequired direction. The housing 22 is mounted on an arm 221 on the lowerend of a screw jack 222, like the screw jacks 1211 and 1419, and mountedon an arm 223 for adjustable movement along said arm in accordance withthe distance of the left-hand continuous traction tread device from theline 127. The arm 223 is in turn mounted on the upper end of a shaft224, adjustable about its axis and held in position by a thumb screw orother securing device 225.

As the machine moves along the line 127, the sensor 217 will send asignal to the motor 216 indicating the tendency of the machine todiverge toward or from the sensor line 127 and how much correction isrequired by the variable flow divider valve 212 to correct this error orvariation from true movement along the line 127. As the motor 216operates the flow divider valve, the volume of oil supplied of the twomotors 15, may be varied to speed up the slow side of the machine andslow down the fast side of the machine.

When the machine is parallel to the line 127 no signal isv required andthe control components are balanced for continued travel of the machinein a direction parallel to the lien 127.

The variable flow divider valve 212 thus receives a constant volume ofoil, which may be regulated by the speed control knob 169, and dividesthe oil to flow through the two pressure lines 213 and 215, inaccordance with the setting of said flow divider valve, by the actuatoror motor 216.

When reverse travel of the machine is required, the manual switch 1811is moved form an automatic to a manual position. The switch 187 is thenmoved to a reverse position to effect energization of a solenoid 1911extending from the valve block 173. This will open the valve in saidvalve block and supply fluid under pressure to a pressure line 227,having connection with a T" 229 dividing the flow through lines 230 and231 between the two motors 15, 15 to effect rotation of said motors inreverse directions. The T" 229 may have a flow divider valve therein, isdesired. The speed control knob 169 may be operated to vary the volumeof flow through the pres sure lines 230 and 231 and the resultant speedof travel of the two motors in reverse directions. The return to tank161) is through return or bleed lines 232 and 233.

When the switch is in its automatic position, and it is desired themachine travel in a forward direction, the switch 187 may be turned to aforward position and the switch 189 may be operated to effect manualsteering of the machine. Steering may be attained by moving the switch189 to the left of a neutral position for turning to the left, or to theright of a neutral position for turning to the right. This switch shouldonly be used when the switch 188 is in an automatic position and duringsteering by this switch, the direction of steering is determined by themeter 197 and needle 1198 of said meter.

When the machine is in operation, the continuous traction tread devices12, 112 usually travel along the subgrade and the curb and gutter areformed between said tread device. Prior to initiating a curb moldingoperation, the line 127 is strung along the left-hand side of themachine and spaced outwardly of the jacks A and B, which suspend oneside of the machine from the associated continuous traction tread device12. The machine may first be brought in position parallel to the line129 by movement of the selector switch 188 to a manual position, and byoperation of the forward-reverse switch 187 and the steering switch 139,manually controlling operation of the motors 15 and manual steering ofthe machine.

The jacks A, B and C may also be adjusted by turning the switch 185 to amanual position and manipulating the switches 183, 181 and 196. When themachine is in the proper position relative to the line 127 the gradesensor members 131 and 115 may be adjusted to come under the line 127 inpositions in advance of opposite ends of the main frame of the machine,to increase the response to tendencies of the machine to vary from thegrade and slope of the roadway. The sensor 219 may then be adjusted tobear against the line 127 and automatically maintain the machine inparallel relation relative to said line.

The selector switches and 128 may then be moved to their automaticpositions with the stop-start valve off and the grade control and travelcontrol knob-s 169 and 199 adjusted to deliver the required volume offluid to the valve blocks 170, 171 and 172, to the variable flow dividervalve 212 and the valve block 173. The start-stop valve 163 may then beturned to an on position to allow fluid to flow.

The motors 15 driving the continuous traction tread devices, beingsupplied with fluid under pressure through the variable flow controlvalve 212, will propel the main frame 11 to draw the mold form 13 inparallel relation with respect to the line 127, under the control of thesensor 219. The main frame 11 will also be maintained in conformancewith the grade and slope of the subgrade by the sensors 131 and 145,engaging under the line 127. As the machine is initially started,concrete is continuously poured into the hopper 60 by a ready-mix truck(not shown) or other source of supply of concrete, which may travel withthe machine.

The draw bar 83 and pivot 93, drawing the mold form along the subgrade,as concrete is poured thereinto, and suspending the mold form from themain frame 111 to effect compression and molding of the concrete asvibrated in the hopper 60 by vibrators and delivered to the mo1d form,thereby attains a uniform curb and gutter smoothed by the smoothing moldform 116 at the trailing end of the mold form.

The mold form is commonly termed a slip mold form because it forms andslips along the formed concrete. The mold form, however, may beinterchanged to conform to local specifications, and the machine andslip mold form may be adjusted to various widths of curbs and guttersand may be used for laying sidewalks, traffic medians, and wideningroadways, by the interchange of different shapes and sizes of moldforms.

it should here be understood that the vibrators in the hopper plus thecompressive action of the mold form limit the need for augers, zeroslump concrete and pea gravel, heretofore used in curb laying machines.

It should further be understood that since the main frame 11 issuspended from the continuous traction tread devices 13 by the jacks A,B and C by a three-point suspension, stabilized by the stabilizer 44that the continuous traction tread devices in addition to riding on thesubgrade may be adjusted by operation of the required jacks so one treaddevice may ride along the pavement while the other tread device may ridealong the subgrade, and with the main frame 11 properly adjustedrelative to the grade by the jacks A, B and C, the roadway may be laidwith the two jacks at different elevations under the control of thesensors 123, 124 and 219. The machine further is readily adapted tovarious operating conditions, and the pivotal connection from the drawbar to the mold form at the front end thereof accommodates the mold formto readily conform to the line of the pavement particulaly where theline may be in the form of a long radius curve.

We claim as our invention:

1. In a curb and gutter forming apparatus, the combination comprising,

a main frame,

a pair of laterally spaced continuous traction tread devices,

a mold form,

a suspension draft connection between said main frame and said moldform, accommodating said mold form to conform to the line of the roadwayupon movement of the apparatus from straight line movement,

comprising a drawbar at the front of said main frame, and

a vertical pivotal connection suspending the front end of said moldframe from said drawbar,

grade and slope conforming connections between said continuous tractiontread devices and said main frame supporting said main frame on saidtraction tread devices and conforming said main frame and mold form tovarious grades and lateral sloping conditions of the roadway.

2. The curb and gutter forming apparatus of claim 1,

wherein a laterally slidable suspending connection is provided betweensaid main frame and the rear end portion of said mold form accommodatinglimited lateral movement of the rear end portion of said mold formrelative to the said main frame about said vertical pivotal connectron.

3. The curb and gear forming apparatus of claim 2,

wherein the suspension connection between the rear end of said mainframe and said mold form adjacent the rear end thereof, a transverse barforming a support for said rollers and accommodating said rollers tomove therealong, and means limiting movement of said rollers along saidbar.

4. The curb and gutter forming apparatus of claim 2,

wherein a hopper extends upwardly of said mold form at the front endthereof and opens to the top of said main frame to supply concrete tosaid mold form, and

wherein means are provided for varying the discharge of concrete fromsaid hopper to said mold form.

5. The curb an gutter forming apparatus of claim 4,

wherein said mold form has a front wall having an open portion at thebottom thereof, accommodating excess concrete to flow through said openportion, to be formed by said mold form upon advance of said main frame,and

wherein means extend in advance of said front wall forwardly alongopposite sides of said open portion, to confine excess concrete to saidopen portion upon advance of said mold form.

6. The curb ad gutter forming apparatus of claim 1,

wherein a three-point suspension is provided between said main frame andsaid continuous traction tread devices, to conform to said main frame,continuous traction tread devices and mold form, to varying slopes andgrades of the roadway.

7. The curb and gutter forming apparatus of claim 6,

wherein the three-point suspension includes two fluid pressure operatedjacks on one side of said main frame, and suspending a first continuoustraction tread device from one side of said main frame, and a singlefluid pressure operated jack on the opposite side of said main framesuspending the other continuous traction tread device from the otherside of said main frame, and

wherein means are provided to control the supply of fluid under pressureto said jacks in accordance with the slope and grade of the roadway.

8. The curb and gutter forming apparatus of claim 7,

wherein said fluid pressure operated jacks each include a hydraulicmotor, and a self-locking screw and nut operated thereby.

9. The curb and gutter forming apparatus of claim 7,

wherein thetwo jacks on one side of said main frame are gradecontrolling jacks and each include a self-locking screw and nut,

wherein an individual fluid pressure operated motor is provided foroperating each of said jacks in accordance with the grade of theroadway,

wherein the single jack on the opposite side of said main frame includesa self-locking screw and nut,

wherein an independent fluid pressure operated motor is provided foroperating said screw and nut, and

wherein a vertical stabilizer guide is provided on the side of the mainframe in association with said one jack, and is pivotally connected tothe associated traction tread device and rigidly secured to said mainframe to guide the associated traction tread device and accommodate thesingle jack to tilt said main frame laterally to conform to thetransverse slope of the roadway.

10. The curb and gutter apparatus of claim 9 wherein a grade sensor isprovided for each grade control jack to individually control operationof said grade controlling jacks,

wherein said grade sensors are located adjacent the front and rear endsof said main frame, and

wherein fluid pressure control means operated by signals generated bysad grade sensors are provided to independently supply fluid underpressure to said grade control jacks in accordance with the grade sensedby said grade sensors.

11. The curb and gutter forming apparatus of claim 9 wherein controlmeans sensing tilting of said main frame about an axis extendinglongitudinally of said main frame, are provided to control the supply offluid under pressure to said third jack in accordance with the slope ofthe roadway.

12. The curb and gutter forming apparatus of claim 10 wherein individualelectrically energizable valve means are provided for each of said gradesensor jacks, and

wherein an electrical energizing connection is provided between each ofsaid grade sensors and an associated electrically energizable valvemeans, to effect the supply of fluid under pressure to said fluidpressure operated motors in accordance with the grade sensed, to rotatesaid motors in one direction or another or to hold said motors fromrotation. 7

13. The curb and gutter forming apparatus of claim 12,

wherein individual electrically energiz'able valve means are provided tocontrol the supply of fluid under pressure to said third fluid pressureoperated motor, and

wherein a slope sensing control, sensing tilting of the apparatus aboutan axis extending longitudinally of said main frame is provided tocontrol energization of said valve means, and the supply of fluid underpressure to said third fluid pressure operated motor, to effect rotationof said third fluid pressure operated motor in one direction or another,or to hold said motor from rotation in accordance with the slope of theroadway.

14. The curb and gutter forming apparatus of claim 1,

wherein individual fluid pressure operated motors are provided to drivesaid traction tread devices, and

wherein a variable flow divider vale is provided to supply fluid underpressure to said motors to effect steering by supplying a greater volumeof fluid to one motor than to the other, and to supply an equal volumeof fluid to each of said motors.

15. The curb and gutter forming apparatus of claim 14,

wherein a reversible electric motor is provided to operate said flowdivider valve and effect steering the vehicle, and

wherein manually operable means are provided to control energization ofsaid motor.

16. The curb and gutter forming apparatus of claim 14,

wherein a reversible electric motor is provided to operate said variableflow divider valve, and

wherein automatic means are provided to control energization of saidmotor in accordance with the line of the roadway.

17. The curb and gutter forming apparatus of claim 16,

wherein the automatic means comprises a line extending along the line ofthe roadway,

a sensor engaging said line, and

electrical circuitry and control means between said line sensor and saidelectric motor and actuated by signals generated by said line sensor toenergize said motor to operate said variable flow divider vale inaccordance with deviation of the machine from said line and the line ofthe roadway.

18. The curb and gutter forming apparatus of claim 17,

wherein manual means are also provided to energize said electricalcircuitry and control means to operable said motor, and vary the flow tosaid hydraulic motors in ac cordance with deviations from said line.

19. The curb and gutter forming apparatus of claim 9,

wherein individual fluid pressure operated motors are provided to drivesaid continuous traction tread devices,

wherein a variable flow divider valve is provided to divide the flow tosaid motors in accordance with the line of the roadway,

wherein a line sensor is provided to effect operation of said flowdivider valve'to supply a uniform volume of fluid to each motor and tosupply a greater volume of fluid to one motor than the other inaccordance with the required line of travel of the apparatus 20. Thecurb and gutter forming apparatus of claim 19,

wherein a reversible motor is provided to operate said flow dividervalve,

wherein said line sensor controls operation of said motor to vary theflow of fluid to said two motors, and

wherein a manually operated switch is provided and electrical controlconnections are provided between said switch and said reversible motorfor effecting variation of said flow divider valve and manual steeringof the machine.

211. In a steering assembly and in combination with a paving machine andthe like,

a main frame,

laterally spaced continuous propelling said main frame,

an individual fluid pressure operated motor for driving each of saidcontinuous traction tread devices,

a source of fluid under pressure,

a flow divider valve,

a fluid pressure connection from said source of fluid under pressure tosaid flow divider valve,

separate fluid pressure connections from said flow divider valve to eachof said motors,

a reversible electric motor having operative connection with said flowdivider valve, operating said valve to supply equal volumes to fluid toeach hydraulic motor and to supply a greater volume of fluid to onemotor than the other in accordance with the line of the roadway,

a sensor and signal generating device operated thereby in W accordancewith a line extending along the roadway, for controlling operation ofsaid motor and the line of travel of the machine,

a manually operable switch effective to connect said signal generatingdevice in the operating circuit for said motor to effect automaticsteering of the machine and to disconnect said signal generating devicefrom said circuit to actraction tread devices commodate manual steeringof the machine, and

a second manually operable switch effective to manually control saidmotor and effect manual steering of the machine.

22. in paving machine,

a main frame,

a pair of laterally spaced continuous traction devices,

a three-point suspension between said continuous traction devices andsaid main frame, for tilting and moving said main frame up and down toconform to the grade and contour of a roadway comprising,

two fluid pressure operated self-locking screw jacks suspending one sideof said main frame from one continuous traction tread device,

a third fluid pressure operated self-locking screw jack suspending theopposite side of said frame from a second of said continuous tractiontread devices,

individual rotary fluid pressure operated motors having direct drivingconnection with each of said screwjacks,

valve means supplying fluid under pressure to two of said motors on oneside of said main frame to conform to the grade of the roadway, and

valve means supplying fluid under pressure to the third of said fluidpressure operated motors independently of said first mentioned valvemeans, to conform said main frame and traction tread devices to thetransverse tilt of the roadway, and

stabilizing guide means connected between said main frame and the secondof said continuous traction tread devices comprising, 7

a vertically extending hollow post mounted on said main frame,cooperating with and extending parallel to said third self-lockin screwjack andsipaced therefrom, a yoke transverse y pivoted to sm tread framein spaced relation with respect to said screw jack, and a guide membertelescopically mounted in said post, and secured to and extendingupwardly of said yoke, and guiding said main frame for up and downmovement relative to said third self-locking screw jack.

HMIHJI unuu

1. In a curb and gutter forming apparatus, the combination comprising, amain frame, a pair of laterally spaced continuous traction treaddevices, a mold form, a suspension draft connection between said mainframe and said mold form, accommodating said mold form to conform to theline of the roadway upon movement of the apparatus from straight linemovement, comprising a drawbar at the front of said main frame, and avertical pivotal connection suspending the front end of said mold framefrom said drawbar, grade and slope conforming connections between saidcontinuous traction tread devices and said main frame supporting saidmain frame on said traction tread devices and conforming said main frameand Mold form to various grades and lateral sloping conditions of theroadway.
 2. The curb and gutter forming apparatus of claim 1, wherein alaterally slidable suspending connection is provided between said mainframe and the rear end portion of said mold form accommodating limitedlateral movement of the rear end portion of said mold form relative tothe said main frame about said vertical pivotal connection.
 3. The curband gear forming apparatus of claim 2, wherein the suspension connectionbetween the rear end of said main frame and said mold form adjacent therear end thereof, a transverse bar forming a support for said rollersand accommodating said rollers to move therealong, and means limitingmovement of said rollers along said bar.
 4. The curb and gutter formingapparatus of claim 2, wherein a hopper extends upwardly of said moldform at the front end thereof and opens to the top of said main frame tosupply concrete to said mold form, and wherein means are provided forvarying the discharge of concrete from said hopper to said mold form. 5.The curb an gutter forming apparatus of claim 4, wherein said mold formhas a front wall having an open portion at the bottom thereof,accommodating excess concrete to flow through said open portion, to beformed by said mold form upon advance of said main frame, and whereinmeans extend in advance of said front wall forwardly along oppositesides of said open portion, to confine excess concrete to said openportion upon advance of said mold form.
 6. The curb ad gutter formingapparatus of claim 1, wherein a three-point suspension is providedbetween said main frame and said continuous traction tread devices, toconform to said main frame, continuous traction tread devices and moldform, to varying slopes and grades of the roadway.
 7. The curb andgutter forming apparatus of claim 6, wherein the three-point suspensionincludes two fluid pressure operated jacks on one side of said mainframe, and suspending a first continuous traction tread device from oneside of said main frame, and a single fluid pressure operated jack onthe opposite side of said main frame suspending the other continuoustraction tread device from the other side of said main frame, andwherein means are provided to control the supply of fluid under pressureto said jacks in accordance with the slope and grade of the roadway. 8.The curb and gutter forming apparatus of claim 7, wherein said fluidpressure operated jacks each include a hydraulic motor, and aself-locking screw and nut operated thereby.
 9. The curb and gutterforming apparatus of claim 7, wherein the two jacks on one side of saidmain frame are grade controlling jacks and each include a self-lockingscrew and nut, wherein an individual fluid pressure operated motor isprovided for operating each of said jacks in accordance with the gradeof the roadway, wherein the single jack on the opposite side of saidmain frame includes a self-locking screw and nut, wherein an independentfluid pressure operated motor is provided for operating said screw andnut, and wherein a vertical stabilizer guide is provided on the side ofthe main frame in association with said one jack, and is pivotallyconnected to the associated traction tread device and rigidly secured tosaid main frame to guide the associated traction tread device andaccommodate the single jack to tilt said main frame laterally to conformto the transverse slope of the roadway.
 10. The curb and gutterapparatus of claim 9 wherein a grade sensor is provided for each gradecontrol jack to individually control operation of said grade controllingjacks, wherein said grade sensors are located adjacent the front andrear ends of said main frame, and wherein fluid pressure control meansoperated by signals generated by sad grade sensors are provided toindependently supply fluid under pressure to said grade control jacks inaccordance wIth the grade sensed by said grade sensors.
 11. The curb andgutter forming apparatus of claim 9 wherein control means sensingtilting of said main frame about an axis extending longitudinally ofsaid main frame, are provided to control the supply of fluid underpressure to said third jack in accordance with the slope of the roadway.12. The curb and gutter forming apparatus of claim 10 wherein individualelectrically energizable valve means are provided for each of said gradesensor jacks, and wherein an electrical energizing connection isprovided between each of said grade sensors and an associatedelectrically energizable valve means, to effect the supply of fluidunder pressure to said fluid pressure operated motors in accordance withthe grade sensed, to rotate said motors in one direction or another orto hold said motors from rotation.
 13. The curb and gutter formingapparatus of claim 12, wherein individual electrically energizable valvemeans are provided to control the supply of fluid under pressure to saidthird fluid pressure operated motor, and wherein a slope sensingcontrol, sensing tilting of the apparatus about an axis extendinglongitudinally of said main frame is provided to control energization ofsaid valve means, and the supply of fluid under pressure to said thirdfluid pressure operated motor, to effect rotation of said third fluidpressure operated motor in one direction or another, or to hold saidmotor from rotation in accordance with the slope of the roadway.
 14. Thecurb and gutter forming apparatus of claim 1, wherein individual fluidpressure operated motors are provided to drive said traction treaddevices, and wherein a variable flow divider vale is provided to supplyfluid under pressure to said motors to effect steering by supplying agreater volume of fluid to one motor than to the other, and to supply anequal volume of fluid to each of said motors.
 15. The curb and gutterforming apparatus of claim 14, wherein a reversible electric motor isprovided to operate said flow divider valve and effect steering thevehicle, and wherein manually operable means are provided to controlenergization of said motor.
 16. The curb and gutter forming apparatus ofclaim 14, wherein a reversible electric motor is provided to operatesaid variable flow divider valve, and wherein automatic means areprovided to control energization of said motor in accordance with theline of the roadway.
 17. The curb and gutter forming apparatus of claim16, wherein the automatic means comprises a line extending along theline of the roadway, a sensor engaging said line, and electricalcircuitry and control means between said line sensor and said electricmotor and actuated by signals generated by said line sensor to energizesaid motor to operate said variable flow divider vale in accordance withdeviation of the machine from said line and the line of the roadway. 18.The curb and gutter forming apparatus of claim 17, wherein manual meansare also provided to energize said electrical circuitry and controlmeans to operable said motor, and vary the flow to said hydraulic motorsin accordance with deviations from said line.
 19. The curb and gutterforming apparatus of claim 9, wherein individual fluid pressure operatedmotors are provided to drive said continuous traction tread devices,wherein a variable flow divider valve is provided to divide the flow tosaid motors in accordance with the line of the roadway, wherein a linesensor is provided to effect operation of said flow divider valve tosupply a uniform volume of fluid to each motor and to supply a greatervolume of fluid to one motor than the other in accordance with therequired line of travel of the apparatus
 20. The curb and gutter formingapparatus of claim 19, wherein a reversible motor is provided to operatesaid flow divider valve, wherein said line sensor controls operation ofsaid motoR to vary the flow of fluid to said two motors, and wherein amanually operated switch is provided and electrical control connectionsare provided between said switch and said reversible motor for effectingvariation of said flow divider valve and manual steering of the machine.21. In a steering assembly and in combination with a paving machine andthe like, a main frame, laterally spaced continuous traction treaddevices propelling said main frame, an individual fluid pressureoperated motor for driving each of said continuous traction treaddevices, a source of fluid under pressure, a flow divider valve, a fluidpressure connection from said source of fluid under pressure to saidflow divider valve, separate fluid pressure connections from said flowdivider valve to each of said motors, a reversible electric motor havingoperative connection with said flow divider valve, operating said valveto supply equal volumes to fluid to each hydraulic motor and to supply agreater volume of fluid to one motor than the other in accordance withthe line of the roadway, a sensor and signal generating device operatedthereby in accordance with a line extending along the roadway, forcontrolling operation of said motor and the line of travel of themachine, a manually operable switch effective to connect said signalgenerating device in the operating circuit for said motor to effectautomatic steering of the machine and to disconnect said signalgenerating device from said circuit to accommodate manual steering ofthe machine, and a second manually operable switch effective to manuallycontrol said motor and effect manual steering of the machine.
 22. Inpaving machine, a main frame, a pair of laterally spaced continuoustraction devices, a three-point suspension between said continuoustraction devices and said main frame, for tilting and moving said mainframe up and down to conform to the grade and contour of a roadwaycomprising, two fluid pressure operated self-locking screw jackssuspending one side of said main frame from one continuous tractiontread device, a third fluid pressure operated self-locking screw jacksuspending the opposite side of said frame from a second of saidcontinuous traction tread devices, individual rotary fluid pressureoperated motors having direct driving connection with each of said screwjacks, valve means supplying fluid under pressure to two of said motorson one side of said main frame to conform to the grade of the roadway,and valve means supplying fluid under pressure to the third of saidfluid pressure operated motors independently of said first mentionedvalve means, to conform said main frame and traction tread devices tothe transverse tilt of the roadway, and stabilizing guide meansconnected between said main frame and the second of said continuoustraction tread devices comprising, a vertically extending hollow postmounted on said main frame, cooperating with and extending parallel tosaid third self-locking screw jack and spaced therefrom, a yoketransversely pivoted to said tread frame in spaced relation with respectto said screw jack, and a guide member telescopically mounted in saidpost, and secured to and extending upwardly of said yoke, and guidingsaid main frame for up and down movement relative to said thirdself-locking screw jack.